Portal Mod installer for Minecraft 1.6.4, introduces the features from within another very different game into the game of Minecraft. When implementing these very unique and intelligent features; the mod developers make sure they do it in such a way that it still fits well with the original theme of minecraft, and also to not change too much of the initial games functions. The game of Portal itself was very amazing in a long list of ways. However, seeing as the game was based around a parkour/puzzle system, you as the player were restricted to what you could and could not do inside the game. However, when installing the Portal mod for Minecraft there is almost null restrictions.
Download: http://www.minecraftinstallers.com/portal-gun-mod-installer/
Home: Minecraft Installers